I approach debugging a complex web app by staying calm and methodical instead of guessing randomly.First, I reproduce the issue reliably. I’ll note the exact steps, browser, device, and any user actions that trigger it. Then I narrow it down: is it frontend, backend, network, or environment-specific? Then I check the basics: console errors, network tab for failed requests or slow responses, React/Vue dev tools for component state, or server logs if I have access. From there I comment out big chunks of code or features to isolate where it breaks, add strategic console logs or breakpoints, and step through the flow. Once I find the root cause I write a small failing test if possible, fix it, and verify across browsers/devices before closing it out.

For full-stack development, I strongly prefer containerizing applications with Docker and orchestrating them via Kubernetes where appropriate. This approach keeps things modular, portable, and easy to integrate with cloud platforms for scalable deployments.On the backend, I like using Node.js for its speed and JavaScript ecosystem, or Flask (Python) when I need something lightweight and rapid for APIs and logic. I typically pair these with relational databases like PostgreSQL or MySQL for structured data.For the frontend, React.js is my go-to. Its component-based architecture makes it easy to build reusable, maintainable UIs and manage state efficiently.

During user testing for our group's software engineering class website, I repeatedly refreshed the leaderboard page on Chrome (Windows 11) to check update speed from LeetCode and Codeforces. After several quick refreshes, it sometimes stuck on the loading spinner with a blank list and no data, occurring about 6 out of 10 times and worsening with multiple tabs open. I reproduced it reliably, then logged the bug: title “Leaderboard shows infinite spinner on rapid page refresh"; environment our Dockerized Spring Boot and Redis setup (latest build); steps to reproduce: 1. Load the leaderboard page and wait for data to appear. 2. Refresh the page quickly 3 to 5 times. Actual result: the spinner never resolves, and the API occasionally returns a 200 status with an empty response body. Expected result: data loads in under 2 seconds on every refresh. Severity: medium-high, as it impacts the core feature. I attached a short screen recording, noted no console errors or obvious Redis issues, and that gave our development team enough to pinpoint a Redis cache timing problem and fix it in the next commit.